It is important in rotary pumps for the bearing of the rotor to be well lubricated at all times, in order to preclude the pump becoming damaged or even fretted, to maintain the free movement of the pump, and to avoid or at least slow up wear on the bearing and/or the rotor.
In known applications, the bearing of a pump is supplied with lubricant via the high-pressure region or an external pressure reservoir, wherein the lubrication of the bearing is generally dependent on a rotational direction of the pump, such that when the rotational direction is reversed, the bearing is connected to the low-pressure region of the pump and is thus no longer supplied with lubricant.